Reliability and Availability Analysis of Database System with Standby Unit Provided by the System Provider

The present paper deals with the study of a database system having Primary database and hot standby database unit which is provided by the system provider itself. There is an agreement with the system provider that on the failure of the hot standby unit, another similar unit is immediately provided by him. The primary unit is a production unit and synchronized with hot standby unit through online transfer of archive redo logs. Data being saved in the primary unit gets simultaneously stored in the hot standby unit. When the primary database unit fails, the hot standby database unit becomes the production database and primary database unit goes under repair. The system is analyzed by making use of semi-Markov processes and regenerative point technique. Expression for Mean Time to System Failure, Mean Time to Failure of Primary Database Unit and Availability of Primary Unit are obtained. Graphical study has also been done.